--- irange.hpp	2011-05-16 12:15:51 +0900
+++ irange.hpp.new	2011-05-16 12:15:58 +0900
@@ -216,9 +216,11 @@
 
         typedef typename range_detail::integer_iterator_with_step<Integer> iterator_t;
 
-        const std::ptrdiff_t last_step
-            = (static_cast<std::ptrdiff_t>(last) - static_cast<std::ptrdiff_t>(first))
-            / (static_cast<std::ptrdiff_t>(step_size));
+        const std::ptrdiff_t last_step =
+            (last==first)
+            ? 0
+            :	(static_cast<std::ptrdiff_t>(last) - static_cast<std::ptrdiff_t>(first) - 1)
+                / (static_cast<std::ptrdiff_t>(step_size)) + 1;
 
         return strided_integer_range<Integer>(
             iterator_t(first, 0, step_size),